1. Field of the Invention
The invention relates to a connector.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2001-110519 discloses a connector with male and female housings that can be connected to one another. A resiliently deformable lock arm is formed like a seesaw on one of the housings and can pivot about a pivot point provided in a longitudinal central part of lock arm. The lock arm can engage the other housing for locking male and female connector housings in a connected state. However, connectors of this type have a potential problem of plastically deforming the lock arm due to excessive deformation when a rear end portion of the lock arm is pulled up by a wire.
To address this problem, a contact projects from a front portion of the lock arm of the above-described connector and contacts a receiving portion on a connector housing to limit resilient deformation of a front end of the lock arm. This prior art design addresses a case where the rear end of the lock arm is displaced in a direction opposite to a normal operating direction (unlocking direction). However, this prior art design provides no consideration for a displacement of the rear end of the lock arm in the normal operating direction. This is because the rear end of the lock arm is thought to be unlikely to be plastically deformed by contacting the upper surface of the connector housing.
A connector used under high temperature often has a housing made of a material containing a glass component. Such a housing has high hardness and flexibility of the lock arm is reduced. Hence, a resiliency limit can be exceeded during resilient deformation with the conventional method of preventing excessive deformation by the contact of the rear end of the lock arm with the upper surface of the connector housing. As a countermeasure, a height from the outer surface of the housing to the rear end of the lock arm may simply be reduced by reducing the height of a pivot point. However, this design option narrows a clearance between the rear end of the lock arm and the outer surface of the housing, thereby complicating efforts of an operator to use a finger to press the rear end of the lock arm down. Thus, the measure to reduce the height of the pivot point is not acceptable.
U.S. Pat. No. 7,160,134 discloses a connector with a terminal accommodating portion to be connected to a mating connector. A lock arm and an unlock arm are formed on the terminal accommodating portion. The lock arm extends forward in a connecting direction with the mating connector from a first support joined to the outer surface of the terminal accommodating portion and is resiliently deformable in directions crossing the connecting direction with the first support as a pivot. The unlock arm includes a locking portion extending forward in the connecting direction from a second support joined to the outer surface of the terminal accommodating portion and an operating portion extending back from the second support. The unlock arm is resiliently deformable like a seesaw in directions crossing the connecting direction with the second support as a pivot.
The lock arm interferes with a lock of the mating connector during a connection process with the mating connector and deforms resiliently in an unlocking direction away from the outer surface of the terminal accommodating portion. The lock arm is restored resiliently when the connector and the mating connector are connected properly and engages the lock to hold the connector and the mating connector in their connected state.
The operating portion is pressed toward the outer surface of the terminal accommodating portion to separate the properly connected connector and mating connector. Thus, the locking portion presses the lock arm in the unlocking direction so that the lock arm disengages from the lock and reaches an unlocked state. The connector and the mating connector are pulled apart with this unlocked state maintained.
A connection space is defined between the outer surface of the terminal accommodating portion and the lock arm to receive part of the mating connector including the lock. The connection space is larger than a space necessary for deformation of the lock arm in the unlocking direction. External matter may interfere with the outer surface of the lock arm and the lock arm may be pressed when the connector is not yet connected to the mating connector. Thus, the lock arm may be deformed toward the outer surface of the terminal accommodating portion beyond a specified resilient deformation amount. This excessive deformation of the lock arm may impair stable locking performance.
U.S. Pat. No. 6,616,481 discloses a connector with a housing that is connectable to a mating housing. A resiliently deformable lock arm is cantilevered from the housing to hold the mating housing in a connected state. Protection walls stand up from the upper surface of the housing at opposite sides of the lock arm. An operating portion is formed at a free end of the lock arm and can be pressed to release a locked state. Preventing pieces project in from inner surfaces of the protection walls. Opposite sides of the operating portion contact the preventing pieces to prevent excessive deformation of the lock arm in a direction opposite an unlocking direction. However, the lock arm may be deformed excessively and beyond resiliency limit in the unlocking direction and may break if the housing is made of a material with a low ductility.
In view of the above situation, an object of the present invention is to provide a connector that can improve overall operability.